The production of extruded open cell mesh is known to the art. Plastic mesh has been used for a variety of purposes, such as mesh bags for fruits and vegetables. Open cell mesh provides a lightweight and strong material for containing relatively heavy objects, while providing the consumer with a relatively unobstructed view of the material contained within the mesh. Such mesh can also be used to make personal cleansing implements.
Prior open cell mesh used to manufacture washing implements has typically been manufactured in tubes through the use of counter-rotating extrusion dies which produce diamond-shaped cells. The extruded tube of mesh is then typically stretched to form hexagonal-shaped cells. The description of a general hexagonal-shaped mesh can be found in U.S. Pat. No. 4,020,208 to Mercer, et al. An example of a counter-rotating die and an extrusion mechanism is described in U.S. Pat. No. 3,957,565 to Livingston, et al. Likewise, square or rectangular webbing has been formed in sheets by two flat reciprocating dies, as shown in U.S. Pat. No. 4,152,479 to Larsen. Although the aforementioned references describe open cell meshes and methods for producing open cell meshes, these references do not describe a soft, resilient product which can be used, for example, as a washing implement. Nor do any of the references listed above define a method of characterizing the softness and resilience of a mesh.
Recently, open cell meshes have been adapted for use as implements for scrubbing, bathing or the like, due to the relative durability and inherent scrubbing characteristics of the mesh. Also, open cell meshes improve lather of soaps in general, and more particularly, the lather of liquid soap is improved significantly when used with an implement made from an open cell mesh. Cleansing ability is generally due to the stiffness of the multiple filaments and nodes of the open cell mesh, causing a friction effect or sensation. To make a scrubbing or bathing implement, the extruded open cell mesh is shaped and bound into one of a variety of final shapes, e.g., a ball, tube, pad or other shape which may be ergonomically friendly to the user of the washing implement. The open cell meshes of the past were acceptable for scrubbing due to the relative stiffness of the fibers and the relatively rough texture of the nodes which bond the fibers together. However, that same stiffness and roughness of prior art mesh was relatively harsh when applied to human skin.
The references described above have been concerned primarily with the strength and durability of the open cell mesh for either containing relatively heavy objects, e.g., fruit and vegetables, or for vigorous scrubbing and cleaning, e.g., of pots and pans. In order to meet the strength and durability requirements, extruded open cell meshes of the past have been manufactured from relatively stiff fibers joined together at nodes whose physical size and shape tended to make them stiff and scratchy, as opposed to soft and conformable.
Hence, heretofore, there has been a continuing need for an improved extruded open cell mesh which would be soft, durable, relatively inexpensive to manufacture, and relatively resilient without being overly stiff and scratchy. More specifically, there was a need for providing an improved open cell mesh, featuring physical characteristics which could be adequately identified and characterized, so that mesh could be reliably made, while exhibiting all of the aforementioned desired physical properties.